Answer:
1.A single band of intermediate density.
Explanation:
According to semiconservative model of DNA replication, the two strands of one DNA molecule separate at the time of replication and each strand acts a template for a new strand. So, the resulting new DNA molecule has one old strand and one new strand.
Here, the E coli cells were grown originally in 14N medium. So all the DNA molecules had 14N strands. When they were transferred to a 15N medium, only 15N was available then for further replications. In the first round of replication in new medium, all the old 14N strands (14N14N) separated and formed a new strand each using 15N. Hence all the resulting DNA molecules had one 14N strand and one 15N strand (14N15N).
Since 14N is of lighter density and 15N is of heavier density, 14N15N strands will give band of intermediate density. Since after one round of replication all DNA molecules will be 14N15N, there will be only one band of intermediate density.
Answer:
components of cell membranes
Answer:
Carbon film is when living thing turned to rock.
petrified fossil is the detail left after an organism decays
Explanation:
Petrified fossils is form when minerals replace the structure of an organism.
Carbon film is a type of fossil found in any rock when organic material is compressed.
D.a protein that attacks foreign molecules
Answer:
b
Explanation:An endothermic chemical reaction provides the energy for ATP hydrolysis in the
The transport of ions across a membrane is powered by the tomat ATP ADP
